George Crumb (born October 24, 1929) is an American composer of modern and avant garde music. He is noted as an explorer of unusual timbres. Examples include spoken flute (one speaks while blowing into the instrument) and glass marbles poured onto an open piano. After initially being influenced by Anton Webern, Crumb became interested in exploring unusual timbres. He often asks for instruments to be played in unusual ways and several of his pieces are written for electrically amplified instruments. Crumb's music often seems to be concerned about the theatre of performance as much as the music itself. In several pieces he asks players to leave and enter the stage during the piece. He has also used unusual layouts of musical notation in a number of his scores. In several pieces, the music is symbolically laid out in a circular or spiral fashion. Black Angels (1970) is a piece which displays Crumb's interest in exploring a wide range of timbres. Written for amplified string quartet (referred to as "electric string quartet" by the composer in the score, although the instruments called for are acoustic ones), the players are required to play various percussion instruments and to bow small goblets as well as to play their instruments in both conventional and unconventional ways. It is one of Crumb's best known pieces, and has been recorded by the Kronos Quartet. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.